Multiple-rate power metering



y 1935- J. P.BALLANTINE 2,000,736

MULTIPLE RATE POWER METERING Filed Nov. 19, 1932 15- @(DGQ) FIG. 11

Patented May 7, 1935 I it I mom invent on .rel tes:to;.kitesratins andreelsms e c r cpowe s eter 21 1118 povnersena insand di tribu in ystems;ther arep r s Ofthe d y, v y of c ursei om oneseasonlof theyear 'tognother durihg whichthe demand for p wer d c nes tol ss than thdesirable minimum the t m shou d eoarr i e. Under these conditions inwater power systerns it is not uncomm nto find-i ne es r t l t wat r otowast which could'be used profitably if the fofi-peak demand for powercould be increased. While the situation in systems operating onoombustible fuel is not so clearly un favoroblere1a tive to ,ofi-' peakrpower periods, itjs folind-that even in those sys ems the large fixedcharges make it desirable to increase the use of power during off-peakperiods as much; as possible. Perhaps-one ofthe' o t important or atprosnti erldi fco dis:

ra es heu eakpowe i t et nvolved nm'te in g th i'scu to rr enerellypay:t

ome p i e os vk owstteho "o :ieners used ho h t isused a t epeako theidsap t teowes de es onnflsr th se w a oe r i e itab e ti he-t: th-Qns1imer .w li

m nt eiiort :fiq us ower:otl eslessoon i nth per od :pf-theds eflfherhsss been is s s s. li t r latin t t e p we ndustr h Pos ib i i fi.-eakpowe a;.1. ate tha ur ng-the ssstifrda fill i tii wh c e s-n tu afloons erabl i al i tia-to overcome. -What isneeded in this-regardis m rpaes nstalle I theimeter n o fl h i nd k eakr e s dt rt eson:v n n M i venio Pro s. w m t ods? r n 311 .8 we h relati e y vimlplewand inexpensiveto pu into; opera tion;,-.;and

means w h w l :m te libo di a a d of a P ma ical aking nt c n .v

the ordinaryiand ofI-peak hours of the s day.

What constitutesmy T int option is set forthi in the-specification iollowing and 1 S-S' l1CCiI 1Qt lyqd ef; v. .l

could be extended easilyio fined-in theeppeiidedfolaims.

1 1M! invention stsh wn dhflairiiwtioififi e .7

O di a ly th wdifll, ki i-1.

showsm y, invention ;-ii1 -a f referred eni- HFIEHre 131: shows.-

oslersco smnedso the 1 11s ita iice s one no can Figures and show a.detailof J orpartof Figure 1;. v

r :In the metering of ordinaryand ofl-peak power,

at he o in r rate ans loiriresi te iiis LthePfi-Z peak energyseparately, soiit cah'be chargedfor at a lower off-peak rate; proofregistering less than t the actual amountof 'oif-peakenergy so that theofi-peak ratewill be automatically lowered below the ordinary rate whenthe aet ai meter rteaJdihg" is billed at the ordinary rate.@h'flttpfiithridi is the simpler of I the 'two-to put into efieoti V Oneway of accomplishing this is'sho' Figure I, another in Figure 11; *IpFigureclock t, p'reierably -'e1ectrioa1ly driveiydfives a -i cam 2. IThe ca'm 2 I :is 'driven' by }the accus -as to complete one revolutionintwemy-rour-'r1ours. Usually ther''is a's in'gleqier iod ofab'c'iutgsix-ijours or less during the day vwhen off-pealg poiveh isavailable. -'On eam Z =the -9lro oonespondizig to rest of the cam.Camjis madeof two similar ports 2a and ZbQ Figure v ,=ea, oh part witha. portion of its are at the larger radius; The two parts I M439:

meters, this type of meter is n c n shown invFi u e wit u cha 1th? to s.isen lt rrz ssiasl 'I;. i 1, s tru r-w d nes l, ase w qiiwhe therein qqesot w some; Ulis s i ,nating watt hour meters.

with airgaps arranged so that in the normal operation the magneticmaterial is not saturated magnetically. Under this condition themagnetic fiux density existingin the iron is on the (straight part ofthe magnetization characteristic of the material, and the flux issubstantially 'propor- 1 tional to the total ampere turns in t hecircuit,

When an alternating voltage is-applied to such gear l1 engages anotherdriving gear 20, depending upon the angular position of cam 2. Thesetwoagears are driven by a shaft 2| which in turn is driven by thedriving disc l3 of the meter. During ordinary periods, the angularposition of cam 2 is such that-the; gears l6 and I9 are engaged,

as shown. in Figure II. During off-peak periods, the cam 2 forces gearsI6 and I? over, disengaging a circuit the flux is built up in themagnetic mate- -1gears, i 6 v and I9 and engaging gears l1 and 20.

rial so that thevoltage is represented by ithe equationz 1 I (1)approximately. In"this'equ'ationE is efiective' voltage, is frequency,12. is number of turns, and c is maximum instantaneous fiux. Theequation where is flux, n is number of turns, I is current, ,u. ispermeability, A is airgap area, and Z is airgap length gives therelationship between flux and currents f .The'fiux in the magneticcircuit can be computed from either of the above equations. In the firstonev it isseen that can be computed independently of the knowledge of I,so for the purpose of explanation of, this invention I need notbeconsideredn In the first equation, 1' can be expressed in terms-ofnasfollows: I 4

inverse proportion to theincrease of n.

Inasmuch as the torque inan induction meter -is an increasing functionof 3 an increase inn,

the number of turns in the circuit, will cause the meter-to have a.lower torque-and to register at a lower rate. By weakening the field ofthe voltage coilthe right amount, any amount of slowing down can beaccomplished. Usually the rate for off-peak poweris about one-half thatfor the ordinary period, so what is done in such an instance is to'makethe meter run only half as fast for a given'amount of energypassingthrough it during'the off-peak period as during-the ordi nary period.This causes register M to indicate only half as 'many kilowatt-hours ofenergy as actuallypass through the meter during the offpeak period. 3The result is that the total reading" of-the meter when paid for at theordinary rate will automatically admit halfthe off -peak periodenergy'free of charge, or stating it another way, will-charge onlyhalf-price for each off-peak kilowatt-hour. Adjustment of tap 9 on coilI l makes itffeasible to change-the ratio of ofi-peak energy toordinaryenergy at, will. If the meterwere adjusted'toregister only one-third'ofthe number of kilowatt-hours passing through. it during offpeak periods,the eifect wou1d, of course, be to admit two-thirds of-the off-peakenergy free, A or,"

Theratio of the diameter of gear 20 to that of so the dial is driven-ata lower speed for a given speed of the driving disc when gears l1 and 20are engaged than when gears l6 and H! are engaged. Accordingly, theoff-peak energy is only partly registered as explained for Figure I.

- In some instances it is desirable to indicate the ordinary andoff-peak energy separately by two registers in the same meter. FigureIII provides a mechanism for accomplishing this. The cam 2 and linkagel5 coact as described for Figure II in shifting a gear 25 on a driveshaft 2| which is connected with the driving disc {3. Two registers l 4and 24 are provided to meter the ordinary and off-peak powerindividually. During ordinary periods cam 2 is in such position thatgear 25 engages and drives gear 26 causing register M to indicate thekilowatt-hours of energy passing through the meter. During off-peakhours, gear 25 is caused by cam 2 to engage and drive gear 21 so thatregister 24 indicates the kilowatt-hours of energy passing through themeter. The result is that register l4 indicates all energy used inordinary periods and register 24 all energy in off-peak periods. The tworeadings can then be charged for separately at their respective rates.FiguresIV and V show certain details of cam 2. Cam 2 iscomposedof'twoparts 2a and 2b which are similar in shape and size. They are placedagainst each other on shaft 3| on which they are held against a shoulder32 by a thumb screw 30, The two cam parts 2a and 2b have portions'oftheir circumference at a greater radius than the rest of it, furthepurpose of imparting motion to otherparts ofthe meter such as the arm 4in Figure I, or linkage l5 in Figure II. The length of arc at thegreater radius is such as to correspond to the minimum length of theoff-peak period with which'the meter is likely to Mooncerned. This is'not the same in all situations but'in most installations is from threeto four hoursout of twenty-four. The entire circumference of the camrepresents twenty-four hours, sofrom one-eighth to one-quarter of itscircumference is at the greater radius. When the two parts 2a and 2b arebrought into coincidence the part of the total circumference at thegreater radius is the minimum period, for example, four hours. If nowone of; the parts-2a or 217 is rotated slightly relativeto the other,the resultant,

part of the circumference of the combined parts at the greatercircumference is greaterthan the minimum amount. By rotating the partstill further, the amount of circumferenceof the greater radius may beincreased to nearly twice the minimum, in this example, eight hours. Byholding both cam parts 2a and 2b to prevent their rotating relative toeach other and turning them together, the ofi-peak registering, periodcan be placed at any position desired in the twenty-four hours,corresponding to a. complete revolution. In most instances, theoff-peakperiod in a day is from four to six hours long, so, two cam parts eachthree or three andone-half hours long would accommodate most practicalrequirements. For other conditions of eitherlshorter or longer periods,cam parts of different peak periods can be used, or anexactly similarone can be placed with the initial two, giving a range of nearly threeto one in the choiceof duration of .the oilpeak period metering. Byseparating the two minimum off-peak parts ofthe circumferences or" thetwo parts 2a and 21), two 'oif peakperiods at different parts of the daycan be accommodated. This is not usually required.

Dial or register indications may bein any units,

not necessarily those usually used in power practice. If desired, anyarbitrary system of numbers can be used during the'ordinary andoif-peak' periods. For example, actual energy unitsmay be indicated inoff-peak periods and some multiple of theenergy units used indicated inordinary periods. read in monetary units directlyif the rate per energyunit were a fixed quantity; If the occurrence of an ofi-peak period isweekly instead of daily, the cams and clock must be changed for slow-errotation.

In the figures, which are diagrammatic, many mechanical and electricaldetails of meters and registering mechanism have for convenience been,

omitted. These are known in the art, and the exact form in which theyare used in my inven- Also, the dials could be calibrated to tion is notsubject to limitations other than those imposed by the requirements ofgood design in metering equipment. i

What I claim is: V i V 1. In a multiple rate metering system the comcoilwith taps, and means for changing said taps for changing the rate ofmetering;

2. In a multiple rate metering system the combination of metering meansincluding a voltage coil in which the number of turns in service ischanged for changing the rate of metering.

3. In a multiple rat e metering system the combination of metering meansincluding a voltage V 5; In a multiple rate metering system thetombination of a tapped voltage coil, contact making, 7

-bination of metering means including a voltage 7 means for changingsaid taps and timingmeans for controlling the changing of the taps ofsaid coil;

6. In a multiple rate metering system'the combination of a tappedvoltage coil and clock operated means for changing the taps of saidcoil.

7. In a multiple rate metering system, the combination of an alternatingcurrent Watthour meter of the induction type including the usual partsand-a tapped voltage coil, and means for changing said taps.

JOHN PERRY BALLANTINE.

